Antifouling paint composition

The antifouling coating composition with copolymer A and an antifouling agent addresses the issues of low solubility and drying in existing films, providing quick drying and long-term performance with enhanced coating film properties.

JP7747346B2Active Publication Date: 2025-10-01NITTO KASEI CO LTD
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Patent Information

Application Number
JP2023503750
Authority / Receiving Office
JP · JP
Patent Type
Patents
Current Assignee / Owner
Priority Date
2021-03-02
Filing Date
2022-02-24
Publication Date
2025-10-01
Estimated Expiration
2042-02-24

AI Technical Summary

Technical Problem

Existing antifouling coating films made of (meth)acrylic acid alkoxycarbonylmethyl ester group-containing polymers have low solubility and insufficient drying, leading to inadequate long-term antifouling performance.

Method used

An antifouling coating composition containing a copolymer A, composed of specific monomers with a weight average molecular weight of 5,000 to 25,000, which includes a compound in general formula (1) with n being 2 or more, and an ethylenically unsaturated monomer, along with an antifouling agent, to enhance coating film solubility and drying.

Benefits of technology

The composition ensures quick drying and maintains excellent coating film surface condition and antifouling performance over a long period, with reduced volatile organic compounds and improved handling properties.

✦ Generated by Eureka AI based on patent content.

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Abstract

Provided is an antifouling coating material composition with good dryness and capable of maintaining a coating film surface in excellent condition and maintaining excellent antifouling performance for a long period of time. The provided antifouling coating material composition contains a copolymer A and an antifouling agent, wherein the copolymer A is a copolymer of (a) a monomer represented by general formula (1) and (b) an ethylenically unsaturated monomer other than the monomer (a), the monomer (a) includes a compound with n in general formula (1) greater than or equal to 2, and the copolymer A has a weight average molecular weight of 5,000-25,000.
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Description

[Technical Field]

[0001] The present invention relates to an antifouling coating composition. [Background technology]

[0002] Aquatic fouling organisms such as barnacles, serpula, mussels, bryozoans, sea squirts, green laver, sea lettuce, slime, etc. attach to ships (especially the bottom of ships), fishing equipment such as fishing nets and fishing net accessories, and underwater structures such as power plant water pipes, causing problems such as impairing the function of these ships and damaging their appearance.

[0003] To prevent such problems, a technique is known in which an antifouling coating composition is applied to a ship or the like to form an antifouling coating film, and an antifouling agent is gradually released from the antifouling coating film, thereby providing antifouling performance over a long period of time (Patent Documents 1 to 4). However, the antifouling coating films made of (meth)acrylic acid alkoxycarbonylmethyl ester group-containing polymers described in Patent Documents 1 to 4 have extremely low coating film solubility, making it difficult for them to exhibit antifouling properties over a long period of time. To solve these problems, a technique has been proposed that dissolves the coating film and allows the antifouling properties to be maintained over a long period of time (Patent Document 5). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Special Publication No. 63-61989 [Patent Document 2] Japanese Patent Application Laid-Open No. 2003-119420 [Patent Document 3] Japanese Patent Application Laid-Open No. 2003-119419 [Patent Document 4] Patent No. 2002-3776 [Patent Document 5] WO2020 / 045211 publication Summary of the Invention [Problem to be solved by the invention]

[0005] The antifouling coating film made of the antifouling coating composition described in Patent Document 5 has improved coating film solubility, but has the problem of insufficient drying of the coating film when sufficient drying time is not available during coating film formation.

[0006] The present invention has been made in view of the above circumstances, and aims to provide an antifouling coating composition that dries quickly and is capable of maintaining excellent coating film surface condition and antifouling performance for a long period of time. [Means for solving the problem]

[0007] According to the present invention, there is provided an antifouling coating composition containing copolymer A and an antifouling agent, wherein said copolymer A is a copolymer of monomer (a) represented by the following general formula (1) and an ethylenically unsaturated monomer (b) other than said monomer (a), said monomer (a) includes a compound in which n in said general formula (1) is 2 or more, and said copolymer A has a weight average molecular weight of 5,000 to 25,000:

[0008] As a result of extensive research into solving the above problems, the present inventors have found that a composition containing copolymer A and an antifouling agent can solve the above problems, and have thus completed the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0009] The present invention will be described in detail below. 1. Composition of antifouling paint composition The antifouling coating composition of the present invention contains copolymer A and an antifouling agent.

[0010] 1-1.Copolymer A Copolymer A is a copolymer of monomer (a) and an ethylenically unsaturated monomer (b) other than monomer (a), and contains monomer units derived from monomer (a) and monomer (b). The content of monomer (a) relative to the total of monomer (a) and monomer (b) is preferably 10 to 90 mass%, more preferably 20 to 70 mass%. Specific examples include 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, and 90 mass%, and may be within a range between any two of the values ​​exemplified here. In this case, coating film solubility is particularly good.

[0011] 1-1-1. Monomer (a) The monomer (a) is represented by the general formula (1).

[0012] [ka]

[0013] In the formula, R 1 represents hydrogen or a methyl group, and R 2 represents hydrogen, a methyl group, or a phenyl group, and R 3 represents an alkoxy group having 1 to 8 carbon atoms or an alkyl group having 1 to 8 carbon atoms which may be substituted with a phenyl group, or represents a phenyl group; and n represents an integer of 1 to 10.

[0014] R 2 is preferably hydrogen or a methyl group.

[0015] R 3 The number of carbon atoms in the alkoxy group or alkyl group is, for example, 1, 2, 3, 4, 5, 6, 7, or 8, and may be within a range between any two of the values ​​exemplified here. 3 is, for example, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a t-butyl group, a 2-ethylhexyl group, a cyclohexyl group, a benzyl group, a phenyl group, a 2-methoxyethyl group, a 4-methoxybutyl group, a vinyl group, or an allyl group, and is preferably a methyl group, an ethyl group, an isopropyl group, or an n-butyl group.

[0016] n represents an integer of 1 to 10, and n is, for example, 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10, and may be within a range between any two of the numerical values ​​exemplified here.

[0017] Monomer (a) includes a compound in which n is 2 or more in general formula (1). When monomer (a) contains a compound in which n is 2 or more, coating film solubility is increased. Monomer (a) may be composed solely of a compound in which n is 2 or more, or may be a mixture of a compound in which n is 1 and a compound in which n is 2 or more.

[0018] The monomer (a) is preferably composed of a monomer (a1) and a monomer (a2). The content of the monomer (a1) in the monomer (a) is preferably 50 to 80% by mass, more preferably 55 to 75% by mass, and particularly preferably 60 to 70% by mass. Compared to the monomer (a2), the monomer (a1) has the property of increasing the coating film strength and decreasing the coating film solubility. For this reason, if the content of the monomer (a1) is too low, the coating film strength tends to decrease, and the coating film surface condition may become easily deteriorated after a long period of time. On the other hand, if the content of the monomer (a1) is too high, the coating film solubility may decrease, resulting in a decrease in antifouling performance.

[0019] <Monomer (a1)> The monomer (a1) is a compound in which n is 1 in the general formula (1), and is represented by the general formula (2).

[0020] [ka]

[0021] R in general formula (2) 1 ~R 3 The explanation for is the same as for general formula (1).

[0022] Examples of the monomer (a1) include methoxycarbonylmethyl (meth)acrylate, ethoxycarbonylmethyl (meth)acrylate, isopropoxycarbonylmethyl (meth)acrylate, n-propoxycarbonylmethyl (meth)acrylate, n-butoxycarbonylmethyl (meth)acrylate, t-butoxycarbonylmethyl (meth)acrylate, 2-ethylhexyloxycarbonylmethyl (meth)acrylate, cyclohexyloxycarbonylmethyl (meth)acrylate, benzyloxycarbonylmethyl (meth)acrylate, phenoxycarbonylmethyl (meth)acrylate, 2-methoxyethoxycarbonylmethyl (meth)acrylate, 4-methoxybutoxycarbonylmethyl (meth)acrylate, allyloxycarbonylmethyl (meth)acrylate, vinyloxycarbonylmethyl (meth)acrylate, 1-(methoxycarbonyl)(meth)acrylate,

[0044] Examples of the acrylate include 1-(ethoxycarbonyl)ethyl (meth)acrylate, 1-(n-propoxycarbonyl)ethyl (meth)acrylate, 1-(isopropoxycarbonyl)ethyl (meth)acrylate, 1-(n-butoxycarbonyl)ethyl (meth)acrylate, 1-(t-butoxycarbonyl)ethyl (meth)acrylate, α-(methoxycarbonyl)benzyl (meth)acrylate, and α-(ethoxycarbonyl)benzyl (meth)acrylate, and preferred examples include methoxycarbonylmethyl (meth)acrylate, ethoxycarbonylmethyl (meth)acrylate, isopropoxycarbonylmethyl (meth)acrylate, n-propoxycarbonylmethyl (meth)acrylate, n-butoxycarbonylmethyl (meth)acrylate, 1-(methoxycarbonyl)ethyl (meth)acrylate, and 1-(ethoxycarbonyl)ethyl (meth)acrylate.

[0023] <Monomer (a2)> The monomer (a2) is a compound in which n in the general formula (1) is at least 2. n in the general formula (1) is preferably 2 to 6 from the viewpoint of long-term antifouling properties.

[0024] Monomer (a2) preferably contains both a compound in which n is 2 and a compound in which n is 3 or greater. Specifically, the mass ratio (n(2) / n(2-10)) is preferably 0.4 to 0.8, more preferably 0.5 to 0.7, calculated on a solid content basis. In this case, stable coating film dissolution tends to be sustained. Specific examples of this value are 0.40, 0.45, 0.50, 0.55, 0.60, 0.65, 0.70, 0.75, and 0.80, and may be within a range between any two of the values ​​exemplified here.

[0025] Examples of the monomer (a2) include methyl di(oxycarbonylmethyl) (meth)acrylate, ethyl di(oxycarbonylmethyl) (meth)acrylate, isopropyl di(oxycarbonylmethyl) (meth)acrylate, n-propyl di(oxycarbonylmethyl) (meth)acrylate, n-butyl di(oxycarbonylmethyl) (meth)acrylate, t-butyl di(oxycarbonylmethyl) (meth)acrylate, 2-ethylhexyl di(oxycarbonylmethyl) (meth)acrylate, cyclohexyl di(oxycarbonylmethyl) (meth)acrylate, di(oxycarbonylmethyl), benzyl (meth)acrylate di(oxycarbonylmethyl), phenyl (meth)acrylate di(oxycarbonylmethyl), 2-methoxyethyl (meth)acrylate di(oxycarbonylmethyl), 4-methoxybutyl (meth)acrylate di(oxycarbonylmethyl), allyl (meth)acrylate di(oxycarbonylmethyl), vinyl (meth)acrylate di(oxycarbonylmethyl), methyl (meth)acrylate di[1-(oxypolycarbonyl)ethyl], ethyl (meth)acrylate di[1-(oxypolycarbonyl)ethyl] )ethyl], n-propyl (meth)acrylate di[1-(oxypolycarbonyl)ethyl], isopropyl (meth)acrylate di[1-(oxypolycarbonyl)ethyl], n-butyl (meth)acrylate di[1-(oxypolycarbonyl)ethyl], t-butyl (meth)acrylate di[1-(oxypolycarbonyl)ethyl], methyl (meth)acrylate di[α-(oxycarbonyl)benzyl], ethyl (meth)acrylate di[α-(oxycarbonyl)benzyl], and preferably methyl (meth)acrylate di(oxycarbonyl) (oxycarbonylmethyl), ethyl (meth)acrylate di(oxycarbonylmethyl), isopropyl (meth)acrylate di(oxycarbonylmethyl), n-propyl (meth)acrylate di(oxycarbonylmethyl), n-butyl (meth)acrylate di(oxycarbonylmethyl), methyl (meth)acrylate di[1-(oxypolycarbonylethyl)], ethyl (meth)acrylate di[1-(oxypolycarbonylethyl)], methyl (meth)acrylate poly(oxycarbonylmethyl), ethyl (meth)acrylate poly(oxycarbonylmethyl),Isopropyl poly(oxycarbonylmethyl) (meth)acrylate, n-propyl poly(oxycarbonylmethyl) (meth)acrylate, n-butyl poly(oxycarbonylmethyl) (meth)acrylate, t-butyl poly(oxycarbonylmethyl) (meth)acrylate, 2-ethylhexyl poly(oxycarbonylmethyl) (meth)acrylate, cyclohexyl poly(oxycarbonylmethyl) (meth)acrylate, benzyl poly(oxycarbonylmethyl) (meth)acrylate, phenyl poly(oxycarbonylmethyl) (meth)acrylate, 2-methoxyethyl poly(oxycarbonylmethyl) (meth)acrylate, 4-methoxybutyl poly(oxycarbonylmethyl) (meth)acrylate, allyl poly(oxycarbonylmethyl) (meth)acrylate, vinyl poly(oxycarbonylmethyl) (meth)acrylate, methyl poly[1-(oxypolycarbonyl)ethyl] (meth)acrylate, ethyl poly[1-(oxypolycarbonyl)ethyl] (meth)acrylate, (meth) Examples thereof include n-propyl acrylate poly[1-(oxypolycarbonyl)ethyl], isopropyl (meth)acrylate poly[1-(oxypolycarbonyl)ethyl], n-butyl (meth)acrylate poly[1-(oxypolycarbonyl)ethyl], t-butyl (meth)acrylate poly[1-(oxypolycarbonyl)ethyl], methyl (meth)acrylate poly[α-(oxycarbonyl)benzyl], and ethyl (meth)acrylate poly[α-(oxycarbonyl)benzyl], and preferably (methyl Examples of such poly(oxycarbonylmethyl) (meth)acrylate include methyl poly(oxycarbonylmethyl) (meth)acrylate, ethyl poly(oxycarbonylmethyl) (meth)acrylate, isopropyl poly(oxycarbonylmethyl) (meth)acrylate, n-propyl poly(oxycarbonylmethyl) (meth)acrylate, n-butyl poly(oxycarbonylmethyl) (meth)acrylate, methyl poly(1-(oxypolycarbonylethyl) (meth)acrylate, and ethyl poly(1-(oxypolycarbonylethyl) (meth)acrylate).

[0026] 1-1-2.Monomer (b) The monomer (b) is an ethylenically unsaturated monomer other than the monomer (a). The monomer (b) can be classified into a monomer (b1) and a monomer (b2). The monomer (b) used in the polymerization of the copolymer A includes one or both of the monomer (b1) and the monomer (b2).

[0027] <Monomer (b1)> The monomer (b1) is represented by the general formula (3). [ka]

[0028] In the formula, R 4 is hydrogen or a methyl group, R 5 ~R 7 are the same or different and each represents a branched alkyl group having 3 to 8 carbon atoms or a phenyl group.

[0029] The number of carbon atoms in the branched alkyl group is, for example, 3, 4, 5, 6, 7, or 8, and may be within a range between any two of the numbers exemplified here. Examples of branched alkyl groups include an isopropyl group, an isopropenyl group, an isobutyl group, an s-butyl group, a t-butyl group, a 1-ethylpropyl group, a 1-methylbutyl group, a 1-methylpentyl group, a 1,1-dimethylpropyl group, a 1,1-dimethylbutyl group, a thexyl group, a cyclohexyl group, a 1,1-dimethylpentyl group, a 1-methylhexyl group, a 1,1-dimethylhexyl group, a 1-methylheptyl group, a 2-methylbutyl group, a 2-ethylbutyl group, a 2,2-dimethylpropyl group, a cyclohexylmethyl group, a 2-ethylhexyl group, a 2-propylpentyl group, and a 3-methylpentyl group. R 5 ~R 7 are preferably the same or different and are an isopropyl group, an isopropenyl group, an s-butyl group, a t-butyl group, a phenyl group, and a 2-ethylhexyl group, and particularly preferably are an isopropyl group and a 2-ethylhexyl group.

[0030] Examples of the monomer (b1) include triisopropylsilyl (meth)acrylate, triisobutylsilyl (meth)acrylate, tri-s-butylsilyl (meth)acrylate, triisopentylsilyl (meth)acrylate, triphenylsilyl meth(meth)acrylate, diisopropylphenylsilyl (meth)acrylate, diisopropylisobutylsilyl (meth)acrylate, diisopropyl-s-butylsilyl (meth)acrylate, diisopropylisopentylsilyl (meth)acrylate, isopropyldiisobutylsilyl (meth)acrylate, isopropyldi-s-butylsilyl (meth)acrylate, t-butyldiisobutylsilyl (meth)acrylate, and (meth)acrylate. Examples of the monomer (b1) include (meth)acrylic acid silyl esters such as t-butyldiisopentylsilyl (meth)acrylate, t-butyldiphenylsilyl (meth)acrylate, diisopropylthexylsilyl (meth)acrylate, diisopropylcyclohexylsilyl (meth)acrylate, tricyclohexylsilyl (meth)acrylate, tri-1,1-dimethylpentylsilyl (meth)acrylate, tri-2,2-dimethylpropylsilyl (meth)acrylate, tricyclohexylmethylsilyl (meth)acrylate, diisopropylcyclohexylmethylsilyl (meth)acrylate, tri-2-ethylhexylsilyl (meth)acrylate, and tri-2-propylpentylsilyl (meth)acrylate. These monomers (b1) can be used alone or in combination of two or more.

[0031] <Monomer (b2)> Monomer (b2) is obtained by removing monomer (b1) from monomer (b). In other words, monomer (b2) is a monomer not represented by any of general formulas (1) to (3). Examples of monomer (b2) include (meth)acrylic acid esters not represented by general formulas (1) to (3), vinyl compounds, aromatic compounds, and dialkyl ester compounds of dibasic acids. In this specification, (meth)acrylic acid esters refer to acrylic acid esters or methacrylic acid esters.

[0032] Examples of (meth)acrylic acid esters not represented by the general formulas (1) to (3) include methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, isobutyl (meth)acrylate, t-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, lauryl (meth)acrylate, 2-methoxyethyl (meth)acrylate, 2-methoxypropyl (meth)acrylate, 4-methoxybutyl (meth)acrylate, benzyl (meth)acrylate, phenyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, propylene glycol monomethyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, and (meth)acrylic acid esters such as 2-hydroxypropyl (meth)acrylate, glycidyl (meth)acrylate, furfuryl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, 2-[2-(2-hydroxyethoxy)ethoxy]ethoxy]ethyl methacrylate, mono(2-(meth)acryloyloxyethyl) succinate, N-(3-dimethylaminopropyl)(meth)acrylamide, 2-hydroxyethyl (meth)acrylate, 2-[2-(2-methoxyethoxy)ethoxy]ethyl (meth)acrylate, and N,N'-dimethyl(meth)acrylamide.

[0033] Examples of vinyl compounds include vinyl compounds having a functional group such as vinyl chloride, vinylidene chloride, acrylonitrile, methacrylonitrile, vinyl acetate, vinyl benzoate, vinyl butyrate, butyl vinyl ether, lauryl vinyl ether, and N-vinylpyrrolidone.

[0034] Examples of aromatic compounds include styrene, vinyltoluene, and α-methylstyrene.

[0035] Examples of dialkyl ester compounds of dibasic acids include dimethyl maleate, dibutyl maleate, and dimethyl fumarate.

[0036] In copolymer A, these monomers (b) can be used alone or in combination of two or more. From the viewpoint of coating film solubility and coating film physical properties, it is preferable that monomer (b) contains a (meth)acrylic acid ester of monomer (b1) or monomer (b2). From the viewpoint of crack resistance, it is preferable that monomer (b) contains a (meth)acrylic acid ester of monomer (b2), and more preferably contains methyl (meth)acrylate, butyl (meth)acrylate, isobutyl (meth)acrylate, t-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, 2-methoxyethyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, glycidyl (meth)acrylate, furfuryl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, or the like. From the viewpoint of coating film solubility, the monomer (b) preferably contains a monomer (b1), and more preferably contains triisopropylsilyl (meth)acrylate, t-butyldiphenylsilyl (meth)acrylate, tri-2-ethylhexylsilyl (meth)acrylate, or the like.

[0037] 1-1-3. Properties and manufacturing method of copolymer A The weight-average molecular weight (Mw) of copolymer A is 5,000 to 25,000. If the molecular weight is less than 5,000, the coating film of the antifouling coating becomes brittle and prone to peeling and cracking, while if it exceeds 25,000, the viscosity of the coating increases when the amount of volatile organic compounds (VOCs) contained in the antifouling coating composition is small, making handling difficult. Specific examples of Mw are 5,000, 7,500, 10,000, 12,500, 15,000, 17,500, 20,000, 22,500, and 25,000, and may be within a range between any two of the numerical values ​​exemplified here.

[0038] The Mw can be measured by, for example, gel permeation chromatography (GPC).

[0039] Copolymer A may be any of a random copolymer, an alternating copolymer, a periodic copolymer, and a block copolymer of monomer (a) and monomer (b).

[0040] Copolymer A can be obtained, for example, by polymerizing monomer (a) and monomer (b) in the presence of a polymerization initiator.

[0041] Examples of the polymerization initiator include azo compounds such as 2,2'-azobisisobutyronitrile, 2,2'-azobis(2-methylbutyronitrile), 2,2'-azobis(2,4-dimethylvaleronitrile), dimethyl-2,2'-azobisisobutyrate, dimethyl 2,2'-azobisisobutyrate, and 2,2'-azobis(N-butyl-2-methylpropionamide); benzoyl peroxide, di-tert-butyl peroxide, and tert-butyl peroxide. Dibenzoate, tert-butylperoxyisopropyl carbonate, t-butylperoxy-2-ethylhexanoate, t-hexylperoxy-2-ethylhexanoate, di-t-hexyl peroxide, t-butylperoxy-2-ethylhexyl monocarbonate, di-t-butyl peroxide, 1,1,3,3-tetramethylbutylperoxyneodecanoate, t-amylperoxyneodecanoate, t-hexylperoxypivalate, Examples of suitable polymerization initiators include peroxides such as t-amyl peroxypivalate and 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate. These polymerization initiators can be used alone or in combination of two or more. As the polymerization initiator, 2,2'-azobisisobutyronitrile, 2,2'-azobis(2-methylbutyronitrile), 2,2'-azobis(2,4-dimethylvaleronitrile), dimethyl 2,2'-azobisisobutyrate, and 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate are particularly preferred. The molecular weight of copolymer A can be adjusted by appropriately setting the amount of polymerization initiator used. A chain transfer agent can also be used to adjust the molecular weight of the resulting polymer. Examples of suitable chain transfer agents include mercaptans such as n-dodecyl mercaptan; thioglycolic acid esters such as octyl thioglycolate; α-methylstyrene dimer, and terpinolene.

[0042] Examples of the polymerization method include solution polymerization, bulk polymerization, emulsion polymerization, suspension polymerization, non-aqueous dispersion polymerization, etc. Among these, solution polymerization or non-aqueous dispersion polymerization is particularly preferred because it allows copolymer A to be obtained easily and accurately.

[0043] In the polymerization reaction, an organic solvent may be used if necessary. The organic solvent is not particularly limited, but examples thereof include aromatic hydrocarbon solvents such as xylene and toluene; aliphatic hydrocarbon solvents; ester solvents such as ethyl acetate, butyl acetate, isobutyl acetate, methoxypropyl acetate, and propylene glycol 1-monomethyl ether 2-acetate; alcohol solvents such as isopropyl alcohol, butyl alcohol, and propylene glycol monomethyl ether; ether solvents such as dioxane, diethyl ether, and dibutyl ether; and ketone solvents such as methyl ethyl ketone and methyl isobutyl ketone. Among these, butyl acetate, isobutyl acetate, butyl alcohol, propylene glycol monomethyl ether, propylene glycol 1-monomethyl ether 2-acetate, toluene, and xylene are preferred. These solvents can be used alone or in combination of two or more.

[0044] The reaction temperature in the polymerization reaction may be appropriately set depending on the type of polymerization initiator, etc., and is usually 50 to 160°C, and preferably 60 to 150°C.

[0045] The polymerization reaction is preferably carried out in an atmosphere of an inert gas such as nitrogen gas or argon gas.

[0046] 1-2. Antifouling agents Antifouling agents include, for example, inorganic agents and organic agents. Examples of inorganic agents include cuprous oxide, copper thiocyanate (common name: copper rhodanide), copper powder, etc. Among these, cuprous oxide and copper rhodanide are particularly preferred, and cuprous oxide that has been surface-treated with glycerin, sucrose, stearic acid, lauric acid, rishitin, mineral oil, etc. is more preferred in terms of long-term storage stability. Examples of organic agents include 2-mercaptopyridine-N-oxide copper (generic name: copper pyrithione), 2-mercaptopyridine-N-oxide zinc (generic name: zinc pyrithione), zinc ethylenebisdithiocarbamate (generic name: zineb), 4,5-dichloro-2-n-octyl-3-isothiazolone (generic name: She-Nine 211), 3,4-dichlorophenyl-NN-dimethylurea (generic name: diuron), 2-methylthio-4-t-butylamino-6-cyclopropylamino-s-triazine (generic name: Irgarol 1051), 2-(p-chlorophenyl)-3-cyano-4-bromo-5-trifluoromethylpyrrole (generic name: Econea 28), and 4-[1-(2,3-dimethylphenyl)ethyl]-1H-imidazole (generic name: medetomidine). These antifouling agents can be used alone or in combination of two or more.

[0047] The content of the antifouling agent in the composition of the present invention is not particularly limited, but is usually 0.1 to 60.0 mass % in terms of solid content. The content of the antifouling agent is, for example, 0.1, 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, or 60 mass %, and may be within a range between any two of the values ​​exemplified here.

[0048] 1-3. Volatile organic compounds (VOCs) The antifouling coating composition of the present invention preferably has a VOC content of less than 400 g / L. In this case, the amount of VOC released into the environment during coating film formation is relatively small. The VOC content is, for example, 100 to 399 g / L, specifically, for example, 100, 150, 200, 250, 300, 310, 320, 330, 340, 350, 360, 370, 380, 390, or 399 g / L, and may be within a range between any two of the values ​​exemplified here.

[0049] The VOC content refers to a value calculated using the following method. First, the volatile content (mass%) in the target sample is determined according to ASTM D2369-07. Next, the specific gravity of the target sample at 25°C is determined according to ASTM D1475-98. Using the obtained specific gravity, the volatile content (mass%) is converted into g / L, which is then used to determine the VOC content.

[0050] Specifically, 0.3±0.1g of the target sample is collected, diluted with 3±1ml of toluene, and dried in a dryer at 110±5°C for 1 hour. The volatile content (wt%) is calculated from the sample weight before and after drying. The specific gravity can be determined using a density cup or pycnometer, and is measured at 25°C. The VOC (g / L) is calculated using this volatile content and specific gravity.

[0051] 1-4. Other additives Furthermore, if necessary, resin components other than copolymer A, elution modifiers, plasticizers, pigments, dyes, antifoaming agents, dehydrating agents, thixotropic agents, organic solvents, etc. can be added to the resin for antifouling coating materials of the present invention to form an antifouling coating material.

[0052] Examples of other resin components include copolymer B and polymer P shown below. Copolymer B is a copolymer of monomer (b1) and monomer (b2) and contains monomer units derived from monomer (b1) and monomer (b2). The content of monomer (b1) relative to the total of monomer (b1) and monomer (b2) is preferably 10 to 90 mass%, more preferably 20 to 70 mass%. Specific examples include 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, and 90 mass%, and may be within a range between any two of the values ​​exemplified here. In this case, coating film solubility is particularly good.

[0053] The polymerization method, initiator, solvent, temperature, other conditions, and method for measuring Mw can be the same as those described for Copolymer A. The content of copolymer B in the composition of the present invention is not particularly limited, but the mass ratio (copolymer B / copolymer A) of the content to copolymer A, calculated as solid content, is usually 0.1 to 0.9, and preferably 0.3 to 0.7. This mass ratio may be, for example, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, or 0.9, or may be within a range between any two of the values ​​exemplified here.

[0054] The polymer P is a polymer obtained by polymerizing the monomer (b2). In the present invention, the monomer (b2) can be used alone or in combination of two or more kinds. In particular, from the viewpoint of compatibility with copolymer A, methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, isobutyl (meth)acrylate, t-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, 2-methoxyethyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, furfuryl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, benzyl (meth)acrylate, and the like are preferred. The polymerization method, initiator, solvent, temperature, other conditions, and method for measuring Mw can be the same as those described for Copolymer A. The content of polymer P in the composition of the present invention is not particularly limited, but the mass ratio (polymer P / copolymer A) of the content to copolymer A, calculated as solid content, is usually 0.1 to 0.5, and preferably 0.1 to 0.3. This mass ratio may be, for example, 0.1, 0.2, 0.3, 0.4, or 0.5, and may be within a range between any two of the values ​​exemplified here.

[0055] Examples of the elution modifier include monocarboxylic acids and their salts, such as rosin, rosin derivatives, naphthenic acid, cycloalkenylcarboxylic acid, bicycloalkenylcarboxylic acid, versatic acid, trimethylisobutenylcyclohexenecarboxylic acid, and metal salts thereof, or the above-mentioned alicyclic hydrocarbon resins. These can be used alone or in combination of two or more. Examples of the rosin derivatives include hydrogenated rosin, disproportionated rosin, maleated rosin, formylated rosin, and polymerized rosin. Examples of commercially available alicyclic hydrocarbon resins include Quinton 1500, 1525L, and 1700 (trade names, manufactured by Zeon Corporation). Of these, rosin, rosin derivatives, naphthenic acid, versatic acid, trimethylisobutenylcyclohexenecarboxylic acid, or metal salts thereof are preferred.

[0056] Examples of the plasticizer include phosphate esters, phthalate esters, adipate esters, sebacate esters, polyesters, epoxidized soybean oil, alkyl vinyl ether polymers, polyalkylene glycols, t-nonyl pentasulfide, petrolatum, polybutene, tris(2-ethylhexyl) trimellitate, silicone oil, chlorinated paraffin, etc. These can be used alone or in combination of two or more.

[0057] Examples of dehydrating agents include calcium sulfate, synthetic zeolite adsorbents, orthoesters, silicates such as tetramethoxysilane and tetraethoxysilane, isocyanates, carbodiimides, carbodiimidazoles, etc. These can be used alone or in combination of two or more.

[0058] 2. Physical properties of antifouling paint composition The antifouling coating composition of the present invention preferably has a viscosity of 80 to 110 KU at 25°C. In this case, the antifouling coating composition is easy to handle and the drying time when forming a coating film is not likely to be long. Specific examples of this viscosity include 80, 85, 90, 95, 100, 105, and 110 KU, and may be within a range between any two of the values ​​exemplified here. The viscosity can be measured by the method shown in the examples.

[0059] 3. Method for producing antifouling coating composition The antifouling coating composition of the present invention can be produced, for example, by mixing and dispersing a mixture containing copolymer A, an antifouling agent, other additives, etc., using a disperser.

[0060] The mixed liquid is preferably one in which various materials such as copolymer A and an antifouling agent are dissolved or dispersed in a solvent. As the dispersing machine, for example, a machine that can be used as a fine grinding machine can be suitably used. For example, a commercially available homomixer, sand mill, bead mill, disperser, etc. can be used. Alternatively, the mixed liquid may be mixed and dispersed using a container equipped with a stirrer and containing glass beads for mixing and dispersion.

[0061] The antifouling coating composition is preferably produced by mixing a solution of copolymer A with an antifouling agent and / or other additives. In this case, the solution of copolymer A preferably has a solids content of 55% by mass or more. If the solids content of the solution of copolymer A is high, the amount of solvent contained in the solution of copolymer A will be reduced, and the VOC content in the antifouling coating composition produced using this can be reduced. This solids content is, for example, 55 to 90% by mass, preferably 55 to 70% by mass, and specifically, for example, 55, 60, 65, 70, 75, 80, 85, or 90% by mass, and may be within a range between any two of the values ​​exemplified here.

[0062] Furthermore, when the dispersibility or solubility of the antifouling agent and / or additives is poor, it is preferable to pre-disperse or dissolve the antifouling agent and / or additives using an additional solvent to form a first liquid, and then mix the first liquid with the solution of copolymer A. This can improve the dispersibility and / or solubility. When the VOC content in the antifouling coating composition is set to a specified value or less, the amount of solvent available for pre-dispersion or dissolution depends on the amount of solvent contained in the solution of copolymer A. Therefore, by increasing the solids content of the solution of copolymer A, the amount of solvent available for pre-dispersion or dissolution can be increased.

[0063] 4. Antifouling treatment method, antifouling coating film, and coated object The antifouling treatment method of the present invention uses the above antifouling coating composition to form an antifouling coating film on the surface of an object to be coated. According to the antifouling treatment method of the present invention, the antifouling coating film gradually dissolves from the surface, allowing the coating surface to be constantly renewed, thereby preventing the adhesion of aquatic fouling organisms. Examples of objects on which a coating film is formed include ships (particularly ship bottoms), fishing equipment, underwater structures, and the like. The thickness of the antifouling coating film may be appropriately set depending on the type of object to be coated, the sailing speed of the ship, the seawater temperature, etc. For example, when the object to be coated is the bottom of a ship, the thickness of the antifouling coating film is usually 50 to 700 μm, and preferably 100 to 600 μm. [Example]

[0064] The following examples will be given to further clarify the features of the present invention, but the present invention is not limited to these examples. In each Production Example, Example, and Comparative Example, % represents % by mass. The weight average molecular weight (Mw) is a value determined by GPC (polystyrene equivalent value). The GPC conditions are as follows. Equipment: Tosoh Corporation HLC-8220GPC Columns: TSKgel SuperHZM-M (2 columns) Flow rate...0.35 mL / min Detector: RI Column thermostatic bath temperature: 40°C Eluent...THF The heating residue is a value measured in accordance with JIS K 5601-1-2:1999 (ISO 3251:1993) "Paint component testing method - heating residue." The viscosity of the coating composition is a value measured at 25°C using a Stormer viscometer in accordance with the provisions of JIS K 5400. The measurement conditions are as follows: Stormer Viscometer: Coating Tester Industrial Stormer Viscometer No. 453 Measurement temperature: 25±0.5℃ Sample volume: 500 ml (fill up to the mark on a 500 ml sample can) Weight: 75-1000g Measurement method: The time it takes for the impeller to make 100 revolutions is measured. Measurements are taken with different weights, and the time it takes to make 100 revolutions is selected from the range of 27 to 33 seconds, with the value closest to 30 seconds being selected. The KU value is calculated using the KU conversion amount from the number of seconds it takes to make 100 revolutions and the mass of the weight used.

[0065] 1. Manufacturing example 1-1. Example of production of monomer (a1) <Production Example 1 (Production of Monomer a1-1)> A four-neck flask equipped with a thermometer, a condenser, a stirrer, and a dropping funnel was charged with 109 g (1.00 mol) of methyl chloroacetate, 72 g (1.00 mol) of acrylic acid, 0.1 g of 4-methoxyphenol, and 500 g of ethyl acetate, and 101 g (1.00 mol) of triethylamine was added dropwise while stirring, keeping the temperature below 40°C. After the addition was complete, the mixture was stirred at 70-80°C for 6 hours. After the reaction was complete, the organic layer was washed with tap water, hydrochloric acid, and sodium bicarbonate water, in that order, and the solvent was then removed by vacuum concentration to obtain 129.7 g of monomer a1-1.

[0066] <Production Examples 2 to 7 (Production of Monomers a1-2 to a1-7)> Monomers a1-2 to a1-7 were obtained by carrying out the reaction using the raw materials shown in Table 1 in the same manner as in Production Example 1. The reaction conditions and yields of Production Examples 1 to 7 are shown in Table 1.

[0067] [Table 1]

[0068] 1-2. Example of production of monomer (a2) <Production Example 8 (Production of Monomer a2-1)> (1st reaction) A four-necked flask equipped with a thermometer, a condenser, and a stirrer was charged with 215 g (1.85 mol) of sodium monochloroacetate, 201 g (1.85 mol) of methyl chloroacetate, and 300 g of N-methyl-2-pyrrolidone, and the mixture was stirred for 6 hours at 70 to 80° C. After completion of the reaction, 500 ml of toluene was charged to the reaction solution, and the organic layer was washed with tap water, hydrochloric acid, and sodium bicarbonate water in that order. The solvent was then distilled off by concentration under reduced pressure, yielding 262 g of methoxycarbonylmethyl chloroacetate.

[0069] (Second reaction) Next, a four-neck flask equipped with a thermometer, a condenser, a stirrer, and a dropping funnel was charged with 200 g (1.20 mol) of methoxycarbonylmethyl chloroacetate (the product of the first reaction), 87 g (1.20 mol) of acrylic acid, 0.1 g of 4-methoxyphenol, and 500 g of ethyl acetate, and 122 g (1.20 mol) of triethylamine was added dropwise while stirring, keeping the temperature below 40°C. After the addition was complete, the mixture was stirred at 70-80°C for 6 hours. After the reaction was complete, the organic layer was washed with tap water, hydrochloric acid, and sodium bicarbonate water, in that order, and the solvent was then removed by vacuum concentration to obtain 230.6 g of monomer a2-1.

[0070] <Production Examples 9 to 42 (Production of Monomers a2-2 to a2-35)> Monomers a2-2 to a2-35 shown in Table 2 were obtained by carrying out reactions using the raw materials shown in Tables 2 to 4 in the same manner as in Production Example 8. The reaction conditions and yields of Production Examples 8 to 42 are shown in Tables 2 to 4.

[0071] [Table 2]

[0072] [Table 3]

[0073] [Table 4]

[0074] Details of the raw materials in Tables 1 to 4 are as follows. AA: acrylic acid MAA: methacrylic acid NMP: N-methyl-2-pyrrolidone CANa: Sodium monochloroacetate CPANa: Sodium 2-chloropropionate CAMe: methyl chloroacetate CAEt: ethyl chloroacetate CAiPr: isopropyl chloroacetate CAnBu: n-butyl chloroacetate CPAMe: 2-chloropropionic acid methyl ester MEHQ: 4-methoxyphenol TEA: Triethylamine

[0075] 1-3. Example of copolymer solution production <Production Example P1 (Production of Copolymer Solution A-1)> A four-neck flask equipped with a thermometer, condenser, stirrer, and dropping funnel was charged with 40 g of xylene and 40 g of propylene glycol monomethyl ether as solvents. Nitrogen gas was introduced and the temperature was maintained at 88°C while stirring. A mixture of monomers (a) and (b) in the amounts (g) shown in Table 5 and 3.0 g (initial addition) of 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate as a polymerization initiator was added dropwise over 3 hours while maintaining the temperature at 88°C. After stirring at 88°C for 1 hour, 0.1 g of 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate was added three times every hour. The mixture was then stirred at the same temperature for another 2 hours and cooled to room temperature to obtain copolymer solution A-1. The heating residue and Mw of A-1 are shown in Table 5.

[0076] <Production Examples P2 to P28 (Production of Copolymer Solutions A-2 to A-23, B-1, and R-1 to R-4)> Copolymer solutions A-2 to A-23, B-1, and R-1 to R-4 were obtained by carrying out the polymerization reaction in the same manner as in Production Example P1, except that the monomers, polymerization initiators, and solvents shown in Tables 5 to 8 were used. The heating residue and Mw of each polymer are shown in Tables 5 to 8. The numerical values ​​for the amounts of raw materials blended in the tables are in grams.

[0077] [Table 5]

[0078] [Table 6]

[0079] [Table 7]

[0080] [Table 8]

[0081] 1-4.Other manufacturing examples

[0082] <Production Example D1 (Production of gum rosin solution)> 300 g of Chinese gum rosin (WW) and 310 g of xylene were placed in a flask equipped with a thermometer, reflux condenser, and stirrer, and the mixture was refluxed under reduced pressure at 70-80°C for 1 hour to dehydrate, yielding a xylene solution of gum rosin (brown, transparent liquid, 50% solids). The residual content of the resulting solution was 50.3%.

[0083] <Production Example D2 (Production of hydrogenated rosin solution)> A xylene solution of hydrogenated rosin (brown, transparent liquid, solid content 50%) was obtained in the same manner as in Production Example D1, except that the Chinese gum rosin (WW) used in Production Example D1 was replaced with hydrogenated rosin. The heating residue of the obtained solution was 50.1%.

[0084] <Production Example D3 (Production of gum rosin zinc salt solution)> 240 g of Chinese gum rosin (WW) and 360 g of xylene were placed in a flask equipped with a thermometer, reflux condenser, and stirrer. 120 g of zinc oxide was then added so that all of the resin acids in the rosin would form zinc salts. The mixture was refluxed and dehydrated under reduced pressure at 70-80°C for 3 hours. The mixture was then cooled and filtered to obtain a xylene solution of gum rosin zinc salt (a dark brown, transparent liquid with a solid content of 50%). The residual content of the resulting solution was 50.2%.

[0085] <Production Example D4 (Production of hydrogenated rosin zinc salt solution)> A xylene solution of hydrogenated rosin zinc salt (dark brown transparent liquid, solids content 50%) was obtained in the same manner as in Production Example D3, except that the Chinese gum rosin (WW) used in Production Example D3 was replaced with hydrogenated rosin. The heating residue of the obtained solution was 50.5%.

[0086] 2. Examples 1 to 36 and Comparative Examples 1 to 4 (Production of Coating Compositions) The components shown in Tables 9 to 13 were blended in the proportions (mass%) shown in the tables, and the resulting mixture was mixed and dispersed with glass beads having a diameter of 1.5 to 2.5 mm to produce coating compositions. The VOC content in the tables was measured using the method described in "1-3. Volatile organic compounds (VOCs)."

[0087] [Table 9]

[0088] [Table 10]

[0089] [Table 11]

[0090] [Table 12]

[0091] [Table 13]

[0092] Details of the components in the table are as follows: <Dissolution modifier> Hydrogenated rosin zinc salt solution: Use the solution produced in Production Example D4 Gum rosin zinc salt solution: Use the solution produced in Production Example D3 Gum rosin solution: Use the solution prepared in Example D1 Hydrogenated rosin solution: Use the one produced in Production Example D2

[0093] <Anti-fouling agent> Cuprous oxide: Product name "NC-301" (manufactured by Nisshin Chemco Co., Ltd.) Copper pyrithione: Product name "Copper Omajin" (manufactured by LONZA Corporation) Sea Nine: Brand name "Sea Nine 211", 4,5-dichloro-2-octyl-4-isothiazolin-3-one (manufactured by R&H), 30% active ingredient in xylene solution Zineb: [ethylenebis(dithiocarbamate)] zinc (manufactured by Ouchi Shinko Chemical Industry Co., Ltd.) Zinc pyrithione: (manufactured by LONZA Corporation) Econea 028: Trade name "Econea 028" 2-(p-chlorophenyl)-3-cyano-4-bromo-5-trifluoromethylpyrrole (manufactured by Janssen PMP) Medetomidine: (±)-4-[1-(2,3-dimethylphenyl)ethyl]-1H-imidazole (Wako Pure Chemical Industries, Ltd.)

[0094] <Pigments> Bengala: Product name: "Bengara Gold" (manufactured by Morishita Bengala Kogyo Co., Ltd.) Talc: Product name "Talc MS" (manufactured by Nippon Talc Co., Ltd.) Zinc oxide: Product name "Zinc Oxide Type 2" (manufactured by Seido Chemical Industry Co., Ltd.) Titanium oxide: Product name "FR-41" (manufactured by Furukawa Co., Ltd.)

[0095] <Other additives> Disparlon A603-20X: Amide-based thixotropic agent: Product name "Disparlon A603-20X" (Kusumoto Chemicals Co., Ltd.) Disparlon 4200-20: Oxidized polyethylene thixotropic agent: Trade name "Disparlon 4200-20" (Kusumoto Chemicals Co., Ltd.) Tetraethoxysilane: Product name "Ethyl Silicate 28" (manufactured by Colcoat Co., Ltd.) Tricresyl phosphate: (manufactured by Daihachi Chemical Industry Co., Ltd.) Chlorinated paraffin: Trade name "Paraffin Chlorinated (Cl: 40%)" (Wako Pure Chemical Industries, Ltd.)

[0096] 3. Exam The coating compositions of the Examples and Comparative Examples were subjected to the following tests. The evaluation results are shown in Tables 9 to 13. In all the comparative examples, the results were not as good as those in the examples in either the rotary test, the antifouling test, or the coating drying test.

[0097] <Test Example 1 (Rotary Test)> A rotating drum with a diameter of 515 mm and a height of 440 mm was installed in the center of the tank and was rotated by a motor. It was also equipped with a cooling device to keep the seawater temperature constant and an automatic pH controller to keep the seawater pH constant.

[0098] Test panels were prepared according to the following method.

[0099] First, an anti-rust paint (epoxy vinyl A / C) was applied to a titanium plate (71 × 100 × 0.5 mm) to a dry thickness of about 100 μm, and then dried to form an anti-rust coating film. Then, the coating compositions obtained in the examples and comparative examples were applied to a dry film thickness of about 300 μm, and the plate was dried at 40°C for 3 days to prepare a test plate.

[0100] The test plate was fixed to the rotating drum of the rotating device of the above-mentioned equipment so that it would come into contact with seawater, and the rotating drum was rotated at a speed of 20 knots. During this time, the seawater temperature was kept at 25°C and the pH at 8.0 to 8.2, and the seawater was replaced every two weeks.

[0101] The remaining film thickness of each test panel was measured initially and every six months after the start of the test using a Keyence VK-X100 shape measuring laser microscope, and the amount of dissolved film per month (μm / month) was obtained by calculating the difference between the measured values. In addition, when measuring the remaining film thickness after 24 months of rotary testing, the surface of each coating was observed with the naked eye and with a microscope to evaluate the surface condition of the coating.

[0102] The coating surface condition was evaluated according to the following criteria. ◎: No abnormalities at all ○: Hair cracks are observed on less than 10% of the total coating surface area △: Hair cracks are observed on 10-30% of the total coating surface area. ×: Hair cracks are observed on more than 30% of the total surface area of ​​the coating film. ××: Abnormalities in the coating such as large cracks, blisters, peeling (only the surface or part of the edge of the coating is peeled off), or delamination (the entire coating is peeled off and no test coating remains)

[0103] <Test Example 2 (Anti-fouling test)> The coating compositions obtained in the Examples and Comparative Examples were applied to both sides of a rigid PVC board (100 x 200 x 2 mm) to a dry coating thickness of approximately 300 μm. The resulting coating was dried at room temperature (25°C) for 3 days to produce a test board with a dry coating thickness of approximately 300 μm. This test board was immersed 1.5 m below sea level in Owase City, Mie Prefecture, and the damage to the test board by deposits was observed after 12 and 24 months.

[0104] The evaluation was carried out by visually observing the state of the coating surface and was judged according to the following criteria. ◎: No adhesion of fouling organisms such as shellfish or algae, and almost no slime. ○: No fouling organisms such as shellfish or algae are attached, and although there is a thin layer of slime (enough to make the coating surface visible), it can be removed by lightly wiping with a brush. △: No adhesion of fouling organisms such as shellfish or algae, but the slime is so thick that the coating surface is not visible and cannot be removed even by wiping vigorously with a brush. ×: Level of fouling organisms such as shellfish and algae adhering

[0105] <Test Example 3 (Paint film drying test)> An epoxy tie coat was applied to a steel plate coated with anti-rust paint to form a dry coating film of 120 μm and allowed to dry. The antifouling paint was then applied to the steel plate to a dry film thickness of 150 μm and allowed to dry for one day. This process was repeated twice to create a test plate with a dry film thickness of 300 μm. This test plate was then dried at room temperature for one or two days, and a 30 mm x 30 mm x 10 mm imitation wood block was placed on the coating surface and subjected to a pressure of 40 kgf / cm in the direction perpendicular to the coating. 2 The paint was pressed at 100°C for 20 minutes, and the condition of the paint film surface was observed after the simulated wood block was removed. Evaluation was based on the following criteria. If the antifouling paint has poor drying properties, the paint film will deform significantly when the simulated wood block is removed, which is undesirable. In Comparative Examples 1 to 4, the paint film deformed due to poor drying properties, which is undesirable. ○: Traces of wood blocks can be observed. △: The periphery of the block is deformed and the paint film is bulging. ×: The periphery of the block was significantly deformed, and a large swelling of the coating film was observed.

Claims

1. An antifouling coating composition containing copolymer A and an antifouling agent, The copolymer A is a copolymer of a monomer (a) represented by the following general formula (1) and an ethylenically unsaturated monomer (b) other than the monomer (a), and the monomer (a) includes a monomer (a1) which is a compound in which n in the general formula (1) is 1, and a monomer (a2) which is a compound in which n in the general formula (1) is 2 or more: the content of the monomer (a1) in the monomer (a) is 50 to 80 mass%; The antifouling coating composition, wherein the copolymer A has a weight average molecular weight of 5,600 to 25,000. 【Chemical 1】 (In the formula, R 1 represents hydrogen or a methyl group, and R 2 represents hydrogen, a methyl group, or a phenyl group, and R 3 represents an alkyl group having 1 to 8 carbon atoms which may be substituted with an alkoxy group having 1 to 8 carbon atoms or a phenyl group, or represents a phenyl group, and n represents an integer of 1 to 10.

2. 2. The antifouling coating composition according to claim 1, wherein the content of volatile organic compounds is less than 400 g / L and the viscosity at 25°C is 80 to 110 KU.

Citation Information

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